I worked with 5 Africans in California. I noticed the same thing. These were all well educated, hard working people. One female, from East Africa, was a Captain in the Air Force Reserve, at Travis AFB, CA.
The ones I have met that are not educated work very hard and their priority is getting their kid’s educated. Nigerians are a very small percentage of the US population but they make up and a good percentage of the black folks at the Ivy league universities. Let’s just hope the Ivy league garbage does not brain wash them.